The Renoster River is a large tributary of the Vaal River in the Free State Province of South Africa.
The river rises at Petrus Steyn and flows northwest past Heilbron into the Koppies Dam. It then flows west past the village of Koppies and later under the N1 national road. Near Viljoenskroon it turns northwest, flows under the R59 and R501 and joins the Vaal River at Renovaal, approximately 25 km east of Orkney. [1]
The Renoster River has a catchment area of approximately 6650 sq. kilometres. The Koppies Dam is the only large dam on the river, and was built primarily for irrigation purposes. The tributaries of the Renoster River are the Doringspruit, Elandspruit, Gelukspruit, Hessebronspruit, Heuningspruit, Karoospruit, Rietspruit and the Vaalbankspruit. [2]